\documentclass{article}
\usepackage{amsopn}
\DeclareMathOperator{\e}{e}

\begin{document}

  \begin{equation}
      \e^{s}\left((nb_{o})^2 - fteb_{o}\right) = 0
  \end{equation}
  
  \begin{equation}
      \e^{s}(n^2b_{o}^2 - fteb_{o}) = 0
  \end{equation}
  
  \begin{equation}
     \e^{s}n^2b_{o}^2 - \e^{s}fteb_{o} = 0
  \end{equation}
  
  \begin{equation}
     \e^{s}n^2b_{o}^2 = \e^{s}fteb_{o}
  \end{equation}
  
  \begin{equation}
     \e^{s}n^2b_{o} = \e^{s}fte
  \end{equation}
  
  \begin{equation}
     \e^{s}nnb_{o} = \e^{s}fte
  \end{equation}
  
  \begin{equation}
     b_{o}nn\e^{s}= fet\e^{s}
  \end{equation}

\end{document}

